Changes between Version 80 and Version 81 of rfc24_progressive_data_support

Timestamp:

Mar 14, 2010, 2:46:36 PM (14 years ago)

Author:

warmerdam

Comment:

update a RasterIO to Reader, and timeout details.

rfc24_progressive_data_support

@@ -11 +11 @@
 == Interfaces ==
 
-=== GDALAsyncRasterIO ===
+=== GDALAsyncReader ===
 
 This new class is intended to represent an active asynchronous raster imagery request.  The request includes information on a source window on the dataset, a target buffer size (implies level of decimation or replication), the buffer type, buffer interleaving, data buffer and bands being requested.  Essentially the same sort of information that is passed in a GDALDataset::!RasterIO() request.  
@@ -19 +19 @@
 While an implementation of the simple accessors is provided as part of the class, it is intended that the class be subclassed as part of implementation of a particular driver, and custom implementations of !GetNextUpdatedRegion(), !LockBuffer() and !UnlockBuffer() provided. 
 
-{{{
-class CPL_DLL GDALAsyncRasterIO
+{{{ 
+class CPL_DLL GDALAsyncReader
 {
   protected:
@@ -40 +40 @@
 
   public:
-    GDALAsyncRasterIO(GDALDataset* poDS = NULL);
-    virtual ~GDALAsyncRasterIO();
+    GDALAsyncReader(GDALDataset* poDS = NULL);
+    virtual ~GDALAsyncReader();
 
     GDALDataset* GetGDALDataset() {return poDS;}
@@ -58 +58 @@
     int GetBandSpace() {return nBandSpace;}
 
-    virtual GDALAsyncStatusType GetNextUpdatedRegion(int nTimeout,
+    virtual GDALAsyncStatusType GetNextUpdatedRegion(double dfTimeout,
                                                      int* pnBufXOff,
                                                      int* pnBufYOff,
@@ -64 +64 @@
                                                      int* pnBufXSize) = 0;
 
-    virtual void LockBuffer() = 0;
-    virtual void UnlockBuffer() = 0; 
+    virtual int LockBuffer( double dfTimeout );
+    virtual void UnlockBuffer(); 
 
     friend class GDALDataset;
@@ -75 +75 @@
 {{{
 GDALAsyncStatusType 
-GDALAsyncRasterio::GetNextUpdatedRegion(int nTimeout,
+GDALAsyncRasterio::GetNextUpdatedRegion(int dfTimeout,
                                         int* pnBufXOff, int* pnBufYOff,
                                         int* pnBufXSize, int* pnBufXSize);
 
-int nTimeout;
-  The amount of time to wait for results measured in milliseconds.  If this is
+int dfTimeout;
+  The amount of time to wait for results measured  in seconds.  If this is
   zero available work may be processed but no waiting for the arrival of more
-  imagery should be done.  Processing available imagery may still take an 
+  imagery should be done.  A value of -1.0 means wait an infinite amount of
+  time for new data.  Processing available imagery may still take an 
   arbitrary amount of time.
 
@@ -116 +117 @@
 
 {{{
-    virtual GDALAsyncRasterIO* 
-        BeginAsyncRasterIO(int nXOff, int nYOff, int nXSize, int nYSize,
+    virtual GDALAsyncReader* 
+        BeginAsyncReader(int nXOff, int nYOff, int nXSize, int nYSize,
                            void *pBuf, int nBufXSize, int nBufYSize,
                            GDALDataType eBufType,
@@ -123 +124 @@
                            int nPixelSpace, int nLineSpace, int nBandSpace,
                            char **papszOptions);
-    virtual void EndAsyncRasterIO(GDALAsyncRasterIO *);
+    virtual void EndAsyncReader(GDALAsyncReader *);
 }}}
 
-It is expected that as part of gdal/gcore a default !GDALAsyncRasterIO implementation will be provided that just uses GDALDataset::!RasterIO() to perform the request as a single blocking request.  However, this default implementation will ensure that applications can use the asynchronous interface without worrying whether a particular format will actually operate asynchronously.
+It is expected that as part of gdal/gcore a default !GDALAsyncReader implementation will be provided that just uses GDALDataset::!RasterIO() to perform the request as a single blocking request.  However, this default implementation will ensure that applications can use the asynchronous interface without worrying whether a particular format will actually operate asynchronously.
 
 === GDALDriver ===
@@ -144 +145 @@
 === C API === 
 
-The following C API wrappers for the C++ classes and methods will be added.  Note that at this time there is no intention to provide C wrappers for all the GDALAsyncRasterIO accessors since the provided information is already available in the application from the call launching the async io. 
+The following C API wrappers for the C++ classes and methods will be added.  Note that at this time there is no intention to provide C wrappers for all the GDALAsyncReader accessors since the provided information is already available in the application from the call launching the async io. 
 
 {{{
-typedef void *GDALAsyncRasterIOH;
+typedef void *GDALAsyncReaderH;
 
 GDALAsyncStatusType CPL_DLL CPL_STDCALL 
-GDALGetNextUpdatedRegion(GDALAsyncRasterIOH hARIO, int nTimeout,
+GDALGetNextUpdatedRegion(GDALAsyncReaderH hARIO, double dfTimeout,
                          int* pnXBufOff, int* pnYBufOff, 
                          int* pnXBufSize, int* pnYBufSize );
-void CPL_DLL CPL_STDCALL GDALLockBuffer(GDALAsyncRasterIOH hARIO);
-void CPL_DLL CPL_STDCALL GDALUnlockBuffer(GDALAsyncRasterIOH hARIO); 
+void CPL_DLL CPL_STDCALL GDALLockBuffer(GDALAsyncReaderH hARIO);
+void CPL_DLL CPL_STDCALL GDALUnlockBuffer(GDALAsyncReaderH hARIO); 
 
-GDALAsyncRasterIOH CPL_DLL CPL_STDCALL 
-GDALBeginAsyncRasterIO(GDALDatasetH hDS, int nXOff, int nYOff,
+GDALAsyncReaderH CPL_DLL CPL_STDCALL 
+GDALBeginAsyncReader(GDALDatasetH hDS, int nXOff, int nYOff,
                        int nXSize, int nYSize,
                        void *pBuf, int nBufXSize, int nBufYSize,
@@ -165 +166 @@
                        char **papszOptions);
 void  CPL_DLL CPL_STDCALL 
-GDALEndAsyncRasterIO(GDALDatasetH hDS, GDALAsyncRasterIOH hAsynchRasterIOH);
+GDALEndAsyncReader(GDALDatasetH hDS, GDALAsyncReaderH hAsynchRasterIOH);
 }}}